SMS Firewall – The Feature you Need in an SMSC

SMS Firewall

It is true that today the world is more connected than ever before and certainly SMS has become a vital tool for businesses to engage with their customers. However, with the increased usage of SMS, there has been an increase in associated data security vulnerabilities owing to the surge of grey router traffic. In order to mitigate these risks, SMS Firewalls came into existence and have become an essential component of an SMSC. Also, the rise in the demand for business in the A2P SMS market is one of the reasons for the growth of the SMS Firewall platform.

According to Research and Markets, one of the leading market research stores, “The Global SMS Firewall Market is estimated to be USD 2.97 Bn in 2021 and is projected to touch USD 4.75 Bn by 2026, increasing at a CAGR of 10%.

Through this post, we will delve into the advantages of having an SMS Firewall and how it can enhance the security and reliability of SMS communications.

What is an SMS Firewall?

An SMS Firewall is a security solution that helps in filtering and blocking unwanted or malicious SMS traffic from reaching mobile devices or phones. We can also say that an SMS Firewall is a security tool meant for protecting mobile networks from unsolicited SMS-based messaging attacks such as SMS spoofing, SMS flooding, SMS faking, and spamming.

Why Do You Need an SMS Firewall in an SMSC?


With the increasing adaptability of corporate SMS, there is a growing need to keep the mobile network secured from vulnerabilities in SMS. Spam and fraudulent messages are harmful to companies as these can tarnish their reputation and also affect their revenue flow. A firewall minimizes these security concerns by protecting the mobile network by automatically detecting and blocking spam.

It is not that the SMS firewall is only about blocking traffic, rather a firewall helps in monetizing the traffic. By monetization, it means identifying which type of SMS traffic will be allowed to pass through the network that can be charged.

Let’s take a look at some of the major reasons why a business needs an SMS firewall in an SMSC:

Prevention of SMS Fraud

SMS Fraud can result in significant financial loss for both the subscribers as well as the business. By deploying an SMS firewall, a business can ensure that fraudulent messages are being identified and blocked. This means that messages containing phishing links or other types of malware get filtered by the SMS firewall.

Staying Compliant with the Regulations

Several countries around the world have regulations to protect consumers from SMS attacks. With the help of an SMS Firewall, a business can stay compliant with these regulations and ensure that only legitimate messages reach the audience.

Maintaining the Reputation of the Business

 SMS attacks like smishing and spam can easily disrupt the reputation of a business and its subscribers. However, with an SMS firewall, a business can maintain a positive reputation by blocking messages that can cause harm to the subscribers.

How does the SMS Firewall Work?

SMS Firewall architecture

SMS firewall scans the inbound SMS traffic in real-time that reaches the network of a mobile operator based on the traffic spikes, and unwanted & repeated content. One can customize the firewall feature and implement various types of rules for different roaming partners, types of sender id, types of traffic, and sources of incoming traffic. Whenever an incoming SMS message matches any of the predefined rules, the SMS Firewall takes appropriate action such as blocking, flagging, or redirecting.

Types of SMS-based Messaging Attacks

Below mentioned are the most commonly executed SMS-based messaging attacks:


This type of attack work by manipulating the sender ID of the SMS messages. This is done to make the message appear from an authentic sender, which in reality is a fake ID displayed to the message recipient. An example includes messages that appear to be sent by government agencies urging the recipient to take actions that can compromise their data security.


SMS Spamming is the sending of unsolicited or irrelevant messages to a large group of audience. These messages generally intend to promote a brand, product, an offer asking the recipients to share their personal data. According to stats, “Around 378,509,197 spam texts were sent/received per day in April 2022.”

SMS Phishing

SMS Phishing or Smishing is an attack technique that tricks mobile network subscribers to share their personal or sensitive information such as credit card details. It is similar to phishing- the only difference is that here SMS  or text messages are the carriers used to deceive and exploit subscribers. SMS Phishing is also used for the spreading of malicious software or malware such as trojans, viruses, and spyware through SMS messages is also an attack technique.

Prevention of SMS-based Messaging Attacks using SMS Firewall

According to a survey of IT professionals and working adults worldwide, in 2022, three in four respondents reported that their organization had encountered smishing attacks. Source – Statista

The role of a firewall solution in the SMS industry is to block unsolicited messages before it reaches the subscribers. The firewall system in the SMS platform whitelists only genuine content to prevent SMS spam. A firewall also helps to control the SMS traffic by putting a check on a large volume of SMS to a single destination. SMS firewalls can efficiently analyze incoming SMS traffic and block any message that appears suspicious or fraudulent. Various techniques such as content filtering and sender ID filtering, reputation-based filtering, etc., are being implemented by SMS Firewalls to prevent SMS Phishing.

Benefits of Having an SMS Firewall in an SMSC

 A Fast and Flexible Platform

As soon as an SMS Firewall is deployed, you can expect it to instantly start working since there are some pre-defined rules which ensure that all known threats are blocked immediately. These firewalls are independent of the device used which allows users to alter their requirements whenever they want.

Blocking the Grey Routes

An SMS Firewall is capable of defending a mobile network against different types of sms based messaging attacks. By blocking all grey routes, an sms firewall strictly prevents any kind of fraudulent activity. All messages that pass from the network are routed through the SMS firewall which analyzes and classifies them including the outbound messages.

Helpful for SMS Aggregators

Today, SMS Firewalls come as an integrated part of A2P SMS platforms or SMS Gateways. With this, SMS firewalls help in eliminating grey routes and getting rid of all spam that could affect a business. SMS aggregators gain significant benefits from this such as reduced costs, increased revenue, and enhanced traffic.

Prevents SMS Spamming

SMS Firewall provides a safe and spam-free network environment by eliminating unwanted SMS spam. This helps in gaining the trust of the customers and certainly reduces the number of customer complaints against illicit messages. Also, it safeguards the business from the overhead cost of processing these unsolicited messages.

Role of SMS Firewall in A2P SMS Monetization

When a mobile operator understands its SMS traffic patterns, it can increase its revenue through the monetization of A2P and other commercial traffic. Monetization channels can be various types of SMS notifications, alerts, or 2-factor authentication sent by e-commerce stores, OTT apps, social, or other financial institutions.

Selecting the Best SMS Firewall for Your SMS Center

It is now clear that an SMS firewall plays a crucial role in the security of a network which means it is important to choose the one that best matches your needs:

Look for a Comprehensive Solution

The primary role of an SMS firewall is to safeguard the network and subscribers from security threats. So make sure the solution you choose has all the security features including content filtering.

User-Friendly Platform

Using an SMS Firewall means that you need to set rules, monitor traffic and manage alerts. So make sure that the SMS Firewall comes with an easy-to-use interface.

Cost-Friendly Platform

Don’t fall for cheap solutions that offer lesser features at attractive prices. You need a robust and feature-rich solution that proves to be the best value for money.

Technical Support

Inquire about the support facility provided by the vendor because you will need it no matter what. Check whether they have a dedicated team of agents and their availability during your business hours to ensure that you are in safe hands.


As an SMS provider, if you want your services to be free from SMS spam, fraud, and other threats, and to improve your subscriber experience, you need to go for an SMS Softswitch with a firewall system. Get in touch with us to learn about REVE SMS Platform.

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Read Also

How to Become a Successful A2P SMS Aggregator?

A2P SMS Monetization – What’s Now and What’s in the Future? 

A2P SMS Market – Growth & Opportunities

Note- This post has been updated with the latest information on 21-04-23.

The Author

Abhijeet Guha

As a dedicated content marketing professional with a passion for crafting engaging pieces within the telecommunications sector, I prioritize thorough research to ensure that every piece of content delivers maximum value.
Abhijeet Guha